It had been a long day of pitched battle, and the mental toll was telling as the Left and Right paddles played their longest game ever with marathon volleys for each hard-fought point.
As it progressed, it appeared to Right that Left was now a curve, then a french fry, and now a pencil as his opponent's imaged wavered. Resolute, Right continued to play until the approaching ball changed to resemble a giant clam opening to eat him. He abandoned the game and ran away screaming.
Lesson: If you are hallucinating while playing, you might need some sleep.